title: Vitamin D deficiency in Serbian patients with Rett syndrome.
abstract: BACKGROUND
  Rett syndrome (RTT) is a severe neurodevelopmental disorder. Bone manifestations of RTT include osteopenia and fractures. Studies addressing serum vitamin D levels in patients with RTT are scarce.
  
  
  OBJECTIVE
  The goals of this study were (1) to determine the prevalence of vitamin D deficiency in patients with RTT, (2) to compare serum vitamin D levels between patients with RTT and those with other neurological diseases, and (3) to explore the correlation between demographic and clinical characteristics of patients with RTT and vitamin D levels.
  
  
  METHODS
  Demographic and clinical characteristics included age, body mass index Z-score, mutation status, clinical severity score, presence of epilepsy, number of antiepileptic drugs, history of fractures, scoliosis, and ambulation ability. Laboratory parameters included serum 25-hydroxyvitamin D [25(OH)D], PTH, calcium, and alkaline phosphatase.
  
  
  RESULTS
  The study included 35 patients with RTT and 35 age-matched females with other neurological diseases. The median serum 25(OH)D concentration in the RTT group was 26.25 nmol/L, with values <75 nmol/L in all participants. Severe deficiency (<25 nmol/L) was detected in 17 of 35 (48.6%) patients. The median 25(OH)D concentration was significantly lower in patients with RTT than in control subjects. The risk for fracture by 12 years of age in patients with RTT was 35.3%. An inverse correlation of the 25(OH)D level to age and PTH level was detected. Patients receiving antiepileptic polytherapy had a 3.3 times greater chance for severe vitamin D deficiency than patients receiving monotherapy.
  
  
  CONCLUSIONS
  The prevalence of vitamin D deficiency in patients with RTT is higher than that in patients with other neurological diseases. The high risk for vitamin D deficiency should be accounted for in the strategy of antiepileptic treatment in RTT, especially when polytherapy is considered.
authors.affiliation: Radoja Dakica Street 6-8, 11070 Novi Beograd, Serbia. adrijans2004@yahoo.com.
authors.forename: Adrijan
authors.initials: A
authors.lastname: Sarajlija
authors.forename: Milena
authors.initials: M
authors.lastname: Djuric
authors.forename: Darija Kisic
authors.initials: DK
authors.lastname: Tepavcevic
authors.forename: Sanja
authors.initials: S
authors.lastname: Grkovic
authors.forename: Maja
authors.initials: M
authors.lastname: Djordjevic
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use; D002112:Calcifediol / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004359:Drug Therapy, Combination / Q000009:adverse effects; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000209:etiology; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D015518:Rett Syndrome / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D012307:Risk Factors; D055771:Serbia / Q000453:epidemiology; D012720:Severity of Illness Index; D014808:Vitamin D Deficiency / Q000139:chemically induced / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; C470125:PTH protein, human; D010281:Parathyroid Hormone; D002112:Calcifediol